2-21007692-C-T

Position:

chr2-21007692-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 5P and 1B. PM2PM5PP5BP4

The NM_000384.3(APOB):c.9176G>A(p.Arg3059His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000155 in 1,613,932 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R3059C) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

APOB
NM_000384.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:3

Conservation

PhyloP100: 0.575

Variant links:

Genes affected

APOB (HGNC:603): (apolipoprotein B) This gene product is the main apolipoprotein of chylomicrons and low density lipoproteins (LDL), and is the ligand for the LDL receptor. It occurs in plasma as two main isoforms, apoB-48 and apoB-100: the former is synthesized exclusively in the gut and the latter in the liver. The intestinal and the hepatic forms of apoB are encoded by a single gene from a single, very long mRNA. The two isoforms share a common N-terminal sequence. The shorter apoB-48 protein is produced after RNA editing of the apoB-100 transcript at residue 2180 (CAA->UAA), resulting in the creation of a stop codon, and early translation termination. Mutations in this gene or its regulatory region cause hypobetalipoproteinemia, normotriglyceridemic hypobetalipoproteinemia, and hypercholesterolemia due to ligand-defective apoB, diseases affecting plasma cholesterol and apoB levels. [provided by RefSeq, Dec 2019]

APOB links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr2-21007693-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 69508.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=2, Uncertain_significance=5, Pathogenic=1}.

PP5

Variant 2-21007692-C-T is Pathogenic according to our data. Variant chr2-21007692-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 490404.We mark this variant Likely_pathogenic, oryginal submissions are: {Pathogenic=1, Uncertain_significance=1}.

BP4

Computational evidence support a benign effect (MetaRNN=0.105754465). . Strength limited to SUPPORTING due to the PP5.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
APOB	NM_000384.3 linkuse as main transcript	c.9176G>A	p.Arg3059His	missense_variant	26/29	ENST00000233242.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
APOB	ENST00000233242.5 linkuse as main transcript	c.9176G>A	p.Arg3059His	missense_variant	26/29	1	NM_000384.3	P1

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152180

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000482

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000120

AC:

AN:

250944

Hom.:

AF XY:

0.00000737

AC XY:

AN XY:

135632

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000151

AC:

AN:

1461752

Hom.:

Cov.:

AF XY:

0.0000110

AC XY:

AN XY:

727180

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000153

Gnomad4 OTH exome

AF:

0.0000662

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152180

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74340

show subpopulations

Gnomad4 AFR

AF:

0.0000482

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000386

Hom.:

Bravo

AF:

0.0000453

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ExAC

AF:

0.00000824

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Uncertain significance, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Uncertain significance, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -

Hypercholesterolemia, autosomal dominant, type B;C4551990:Familial hypobetalipoproteinemia 1

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Nov 25, 2023

This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 3059 of the APOB protein (p.Arg3059His). This variant is present in population databases (rs781645624, gnomAD 0.006%). This missense change has been observed in individuals with clinical features of familial hypercholesterolemia (PMID: 34456049; Invitae). ClinVar contains an entry for this variant (Variation ID: 490404). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt APOB protein function with a negative predictive value of 95%. This variant disrupts the p.Arg3059 amino acid residue in APOB. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 22408029). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 13, 2023

The p.R3059H variant (also known as c.9176G>A), located in coding exon 26 of the APOB gene, results from a G to A substitution at nucleotide position 9176. The arginine at codon 3059 is replaced by histidine, an amino acid with highly similar properties. This variant has been detected in individuals with hypercholesterolemia (external communication). This amino acid position is poorly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.078

BayesDel_addAF

Benign

-0.39

BayesDel_noAF

Benign

-0.63

CADD

Benign

DANN

Uncertain

0.97

Eigen

Benign

-0.53

Eigen_PC

Benign

-0.37

FATHMM_MKL

Benign

0.25

M_CAP

Benign

0.0061

MetaRNN

Benign

0.11

MetaSVM

Benign

-1.1

MutationTaster

Benign

1.0

PrimateAI

Benign

0.34

PROVEAN

Benign

-0.040

REVEL

Benign

0.096

Sift

Benign

0.052

Sift4G

Uncertain

0.0050

Vest4

0.099

MVP

0.49

MPC

0.048

ClinPred

0.11

GERP RS

4.0

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

gMVP

0.33

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over